Emit explicit element type for nullable value type arrays in CSharpHe…

[ilkertskn]

…lper

• A non-empty array literal is normally emitted as an implicitly-typed array (new[] { ... }), but nullable value type elements are rendered as their underlying type, so the array is inferred as the non-nullable type (e.g. int[] instead of int?[]), producing code that does not compile
• Emit the element type explicitly for nullable value type arrays, matching the existing handling for byte and object arrays
• Add tests for nullable value type arrays with and without null elements

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        Summary of the changes
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        Fixes #bugnumber

• Tests for the changes have been added (for bug fixes / features)
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[ilkertskn]

@dotnet-policy-service agree

[Copilot]

Pull request overview

Fixes C# literal generation for arrays of nullable value types in CSharpHelper by ensuring the emitted array literal preserves the intended nullable element type (e.g. int?[]) instead of being inferred as the underlying non-nullable type (e.g. int[]), which can cause generated code to fail compilation when assigned/used as T?[].

Changes:

• Emit an explicit element type for non-empty arrays when the element type is a nullable value type (Nullable<T>), avoiding incorrect implicit array type inference.
• Add coverage to CSharpHelperTest for nullable value type arrays both with and without null elements.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
test/EFCore.Design.Tests/Design/Internal/CSharpHelperTest.cs	Adds tests asserting correct literal emission for int?[] arrays (with/without null).
src/EFCore.Design/Design/Internal/CSharpHelper.cs	Updates array literal emission to explicitly include the nullable element type for Nullable<T> arrays.